The human race has one really effective weapon, and that is laughter.

Psychological theories must pass the test of practical experience.

一种善行没有内心的支持就不会长久，一种行为如果得不到自身的了解就无法树立。 

世界是一本书，不旅行的人只读了一页。

Innovation in mining technology isn't an option—it's an obligation we owe to both our workers and the environment.

跨行业的合作是解决我们面临的复杂能源挑战的关键。